1077 lines
28 KiB
C
1077 lines
28 KiB
C
/*
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* The mrouted program is covered by the license in the accompanying file
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* named "LICENSE". Use of the mrouted program represents acceptance of
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* the terms and conditions listed in that file.
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*
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* The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
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* Leland Stanford Junior University.
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*
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*
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* $Id: route.c,v 1.8 1994/08/24 23:54:42 thyagara Exp $
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*/
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#include "defs.h"
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/*
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* Exported variables.
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*/
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int routes_changed; /* 1=>some routes have changed */
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int delay_change_reports; /* 1=>postpone change reports */
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/*
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* Private variables.
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*/
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static struct rtentry *routing_table; /* pointer to list of route entries */
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static struct rtentry *rtp; /* pointer to a route entry */
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unsigned int nroutes; /* current number of route entries */
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/*
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* Initialize the routing table and associated variables.
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*/
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void init_routes()
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{
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routing_table = NULL;
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nroutes = 0;
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routes_changed = FALSE;
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delay_change_reports = FALSE;
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}
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/*
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* Initialize the children and leaf bits for route 'r', along with the
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* associated dominant, subordinate, and leaf timing data structures.
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* Return TRUE if this changes the value of either the children or
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* leaf bitmaps for 'r'.
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*/
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static int init_children_and_leaves(r, parent)
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register struct rtentry *r;
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register vifi_t parent;
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{
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register vifi_t vifi;
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register struct uvif *v;
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vifbitmap_t old_children, old_leaves;
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VIFM_COPY(r->rt_children, old_children);
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VIFM_COPY(r->rt_leaves, old_leaves );
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VIFM_CLRALL(r->rt_children);
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VIFM_CLRALL(r->rt_leaves);
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r->rt_flags &= ~RTF_LEAF_TIMING;
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for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
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r->rt_dominants [vifi] = 0;
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r->rt_subordinates[vifi] = 0;
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if (vifi != parent && !(v->uv_flags & (VIFF_DOWN|VIFF_DISABLED))) {
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VIFM_SET(vifi, r->rt_children);
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if (v->uv_neighbors == NULL) {
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VIFM_SET(vifi, r->rt_leaves);
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r->rt_leaf_timers[vifi] = 0;
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}
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else {
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r->rt_leaf_timers[vifi] = LEAF_CONFIRMATION_TIME;
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r->rt_flags |= RTF_LEAF_TIMING;
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}
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}
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else {
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r->rt_leaf_timers[vifi] = 0;
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}
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}
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return (!VIFM_SAME(r->rt_children, old_children) ||
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!VIFM_SAME(r->rt_leaves, old_leaves));
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}
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/*
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* A new vif has come up -- update the children and leaf bitmaps in all route
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* entries to take that into account.
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*/
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void add_vif_to_routes(vifi)
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register vifi_t vifi;
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{
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register struct rtentry *r;
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register struct uvif *v;
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v = &uvifs[vifi];
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for (r = routing_table; r != NULL; r = r->rt_next) {
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if (r->rt_metric != UNREACHABLE &&
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!VIFM_ISSET(vifi, r->rt_children)) {
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VIFM_SET(vifi, r->rt_children);
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r->rt_dominants [vifi] = 0;
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r->rt_subordinates[vifi] = 0;
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if (v->uv_neighbors == NULL) {
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VIFM_SET(vifi, r->rt_leaves);
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r->rt_leaf_timers[vifi] = 0;
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}
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else {
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VIFM_CLR(vifi, r->rt_leaves);
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r->rt_leaf_timers[vifi] = LEAF_CONFIRMATION_TIME;
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r->rt_flags |= RTF_LEAF_TIMING;
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}
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update_table_entry(r);
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}
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}
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}
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/*
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* A vif has gone down -- expire all routes that have that vif as parent,
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* and update the children bitmaps in all other route entries to take into
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* account the failed vif.
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*/
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void delete_vif_from_routes(vifi)
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register vifi_t vifi;
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{
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register struct rtentry *r;
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for (r = routing_table; r != NULL; r = r->rt_next) {
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if (r->rt_metric != UNREACHABLE) {
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if (vifi == r->rt_parent) {
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del_table_entry(r, 0, DEL_ALL_ROUTES);
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r->rt_timer = ROUTE_EXPIRE_TIME;
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r->rt_metric = UNREACHABLE;
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r->rt_flags |= RTF_CHANGED;
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routes_changed = TRUE;
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}
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else if (VIFM_ISSET(vifi, r->rt_children)) {
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VIFM_CLR(vifi, r->rt_children);
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VIFM_CLR(vifi, r->rt_leaves);
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r->rt_subordinates[vifi] = 0;
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r->rt_leaf_timers [vifi] = 0;
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update_table_entry(r);
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}
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else {
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r->rt_dominants[vifi] = 0;
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}
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}
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}
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}
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/*
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* A neighbor has failed or become unreachable. If that neighbor was
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* considered a dominant or subordinate router in any route entries,
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* take appropriate action.
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*/
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void delete_neighbor_from_routes(addr, vifi)
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register u_long addr;
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register vifi_t vifi;
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{
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register struct rtentry *r;
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register struct uvif *v;
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v = &uvifs[vifi];
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for (r = routing_table; r != NULL; r = r->rt_next) {
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if (r->rt_metric != UNREACHABLE) {
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if (r->rt_dominants[vifi] == addr) {
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VIFM_SET(vifi, r->rt_children);
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r->rt_dominants [vifi] = 0;
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r->rt_subordinates[vifi] = 0;
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if (v->uv_neighbors == NULL) {
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VIFM_SET(vifi, r->rt_leaves);
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r->rt_leaf_timers[vifi] = 0;
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}
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else {
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VIFM_CLR(vifi, r->rt_leaves);
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r->rt_leaf_timers[vifi] = LEAF_CONFIRMATION_TIME;
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r->rt_flags |= RTF_LEAF_TIMING;
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}
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update_table_entry(r);
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}
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else if (r->rt_subordinates[vifi] == addr) {
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r->rt_subordinates[vifi] = 0;
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if (v->uv_neighbors == NULL) {
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VIFM_SET(vifi, r->rt_leaves);
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update_table_entry(r);
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}
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else {
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r->rt_leaf_timers[vifi] = LEAF_CONFIRMATION_TIME;
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r->rt_flags |= RTF_LEAF_TIMING;
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}
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}
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else if (v->uv_neighbors == NULL &&
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r->rt_leaf_timers[vifi] != 0) {
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VIFM_SET(vifi, r->rt_leaves);
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r->rt_leaf_timers[vifi] = 0;
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update_table_entry(r);
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}
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}
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}
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}
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/*
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* Prepare for a sequence of ordered route updates by initializing a pointer
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* to the start of the routing table. The pointer is used to remember our
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* position in the routing table in order to avoid searching from the
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* beginning for each update; this relies on having the route reports in
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* a single message be in the same order as the route entries in the routing
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* table.
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*/
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void start_route_updates()
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{
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rtp = (struct rtentry *)&routing_table;
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}
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/*
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* Starting at the route entry following the one to which 'rtp' points,
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* look for a route entry matching the specified origin and mask. If a
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* match is found, return TRUE and leave 'rtp' pointing at the found entry.
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* If no match is found, return FALSE and leave 'rtp' pointing to the route
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* entry preceding the point at which the new origin should be inserted.
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* This code is optimized for the normal case in which the first entry to
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* be examined is the matching entry.
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*/
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static int find_route(origin, mask)
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register u_long origin, mask;
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{
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register struct rtentry *r;
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r = rtp->rt_next;
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while (r != NULL) {
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if (origin == r->rt_origin && mask == r->rt_originmask) {
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rtp = r;
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return (TRUE);
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}
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if (ntohl(mask) > ntohl(r->rt_originmask) ||
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(mask == r->rt_originmask &&
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ntohl(origin) > ntohl(r->rt_origin))) {
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rtp = r;
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r = r->rt_next;
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}
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else break;
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}
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return (FALSE);
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}
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/*
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* Search the entire routing table, looking for an entry which conflicts
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* with the given origin and mask, for example, an entry which has the same
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* origin under a different mask. If a conflicting entry is found, return
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* a pointer to the entry preceding it (to facilitate deletion); if no
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* conflict is found, return NULL.
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*/
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static struct rtentry *find_conflicting_route(origin, mask)
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register u_long origin, mask;
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{
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register struct rtentry *r, *prev_r;
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for (prev_r = (struct rtentry *)&routing_table, r = routing_table;
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r != NULL;
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prev_r = r, r = r->rt_next ) {
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if ((origin & r->rt_originmask) == r->rt_origin ||
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(r->rt_origin & mask) == origin) {
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return (prev_r);
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}
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}
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return (NULL);
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}
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/*
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* Create a new routing table entry for the specified origin and link it into
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* the routing table. The shared variable 'rtp' is assumed to point to the
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* routing entry after which the new one should be inserted. It is left
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* pointing to the new entry.
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*
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* Only the origin, originmask, originwidth and flags fields are initialized
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* in the new route entry; the caller is responsible for filling in the the
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* rest.
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*/
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static void create_route(origin, mask)
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u_long origin, mask;
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{
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register struct rtentry *r;
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if ((r = (struct rtentry *) malloc(sizeof(struct rtentry)
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+ (3 * numvifs * sizeof(u_long)))) == NULL) {
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log(LOG_ERR, 0, "ran out of memory"); /* fatal */
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}
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r->rt_origin = origin;
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r->rt_originmask = mask;
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if (((char *)&mask)[3] != 0) r->rt_originwidth = 4;
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else if (((char *)&mask)[2] != 0) r->rt_originwidth = 3;
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else if (((char *)&mask)[1] != 0) r->rt_originwidth = 2;
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else r->rt_originwidth = 1;
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r->rt_flags = 0;
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r->rt_dominants = (u_long *)(r + 1);
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r->rt_subordinates = (u_long *)(r->rt_dominants + numvifs);
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r->rt_leaf_timers = (u_long *)(r->rt_subordinates + numvifs);
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r->rt_next = rtp->rt_next;
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rtp->rt_next = r;
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rtp = r;
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++nroutes;
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}
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/*
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* Discard the routing table entry following the one to which 'prev_r' points.
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*/
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static void discard_route(prev_r)
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register struct rtentry *prev_r;
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{
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register struct rtentry *r;
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r = prev_r->rt_next;
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prev_r->rt_next = r->rt_next;
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free((char *)r);
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--nroutes;
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}
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/*
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* Process a route report for a single origin, creating or updating the
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* corresponding routing table entry if necessary. 'src' is either the
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* address of a neighboring router from which the report arrived, or zero
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* to indicate a change of status of one of our own interfaces.
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*/
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void update_route(origin, mask, metric, src, vifi)
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u_long origin, mask;
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int metric;
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u_long src;
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vifi_t vifi;
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{
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register struct rtentry *r;
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struct rtentry *prev_r;
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int adj_metric;
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/*
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* Compute an adjusted metric, taking into account the cost of the
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* subnet or tunnel over which the report arrived, and normalizing
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* all unreachable/poisoned metrics into a single value.
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*/
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if (src != 0 && (metric < 1 || metric >= 2*UNREACHABLE)) {
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log(LOG_WARNING, 0,
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"%s reports out-of-range metric %u for origin %s",
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inet_fmt(src, s1), metric, inet_fmts(origin, mask, s2));
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return;
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}
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adj_metric = metric + uvifs[vifi].uv_metric;
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if (adj_metric > UNREACHABLE) adj_metric = UNREACHABLE;
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/*
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* Look up the reported origin in the routing table.
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*/
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if (!find_route(origin, mask)) {
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/*
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* Not found.
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* Don't create a new entry if the report says it's unreachable,
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* or if the reported origin and mask are invalid.
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*/
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if (adj_metric == UNREACHABLE) {
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return;
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}
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if (src != 0 && !inet_valid_subnet(origin, mask)) {
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log(LOG_WARNING, 0,
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"%s reports an invalid origin (%s) and/or mask (%08x)",
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inet_fmt(src, s1), inet_fmt(origin, s2), ntohl(mask));
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return;
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}
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/*
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* If the new origin and mask are inconsistent with an entry
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* already in the routing table, either ignore this update
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* (if it came from another router), or delete the conflicting
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* entry (if the update is for a directly-connected subnet).
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*/
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if ((prev_r = find_conflicting_route(origin, mask)) != NULL ) {
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if (src != 0) {
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log(LOG_INFO, 0,
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"%s reports a conflicting origin (%s) and mask (%08x)",
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inet_fmt(src, s1), inet_fmt(origin, s2), ntohl(mask));
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return;
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}
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else {
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r = prev_r->rt_next;
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log(LOG_INFO, 0,
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"deleting route with conflicting origin (%s), mask (%08x)",
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inet_fmt(r->rt_origin, s1), ntohl(r->rt_originmask));
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if (r->rt_metric != UNREACHABLE) {
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del_table_entry(r, 0, DEL_ALL_ROUTES);
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}
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discard_route(prev_r);
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if (rtp == r) rtp = prev_r;
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}
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}
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/*
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* OK, create the new routing entry. 'rtp' will be left pointing
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* to the new entry.
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*/
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create_route(origin, mask);
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rtp->rt_metric = UNREACHABLE; /* temporary; updated below */
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}
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/*
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* We now have a routing entry for the reported origin. Update it?
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*/
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r = rtp;
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if (r->rt_metric == UNREACHABLE) {
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/*
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* The routing entry is for a formerly-unreachable or new origin.
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* If the report claims reachability, update the entry to use
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* the reported route.
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*/
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if (adj_metric == UNREACHABLE)
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return;
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r->rt_parent = vifi;
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init_children_and_leaves(r, vifi);
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r->rt_gateway = src;
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r->rt_timer = 0;
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r->rt_metric = adj_metric;
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r->rt_flags |= RTF_CHANGED;
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routes_changed = TRUE;
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update_table_entry(r);
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}
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else if (src == r->rt_gateway) {
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/*
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* The report has come either from the interface directly-connected
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* to the origin subnet (src and r->rt_gateway both equal zero) or
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* from the gateway we have chosen as the best first-hop gateway back
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* towards the origin (src and r->rt_gateway not equal zero). Reset
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* the route timer and, if the reported metric has changed, update
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* our entry accordingly.
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*/
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r->rt_timer = 0;
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if (adj_metric == r->rt_metric)
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return;
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if (adj_metric == UNREACHABLE) {
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del_table_entry(r, 0, DEL_ALL_ROUTES);
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r->rt_timer = ROUTE_EXPIRE_TIME;
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}
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else if (adj_metric < r->rt_metric) {
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if (init_children_and_leaves(r, vifi)) {
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update_table_entry(r);
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}
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}
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r->rt_metric = adj_metric;
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r->rt_flags |= RTF_CHANGED;
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routes_changed = TRUE;
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}
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else if (src == 0 ||
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(r->rt_gateway != 0 &&
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(adj_metric < r->rt_metric ||
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(adj_metric == r->rt_metric &&
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r->rt_timer >= ROUTE_SWITCH_TIME)))) {
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/*
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* The report is for an origin we consider reachable; the report
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* comes either from one of our own interfaces or from a gateway
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* other than the one we have chosen as the best first-hop gateway
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* back towards the origin. If the source of the update is one of
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* our own interfaces, or if the origin is not a directly-connected
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* subnet and the reported metric for that origin is better than
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* what our routing entry says, update the entry to use the new
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* gateway and metric. We also switch gateways if the reported
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* metric is the same as the one in the route entry and the gateway
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* associated with the route entry has not been heard from recently.
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* Did you get all that?
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*/
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if (r->rt_parent != vifi || adj_metric < r->rt_metric) {
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r->rt_parent = vifi;
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if (init_children_and_leaves(r, vifi)) {
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update_table_entry(r);
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}
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}
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r->rt_gateway = src;
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r->rt_timer = 0;
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r->rt_metric = adj_metric;
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r->rt_flags |= RTF_CHANGED;
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routes_changed = TRUE;
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}
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else if (vifi != r->rt_parent) {
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/*
|
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* The report came from a vif other than the route's parent vif.
|
|
* Update the children and leaf info, if necessary.
|
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*/
|
|
if (VIFM_ISSET(vifi, r->rt_children)) {
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/*
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* Vif is a child vif for this route.
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*/
|
|
if (metric < r->rt_metric ||
|
|
(metric == r->rt_metric &&
|
|
ntohl(src) < ntohl(uvifs[vifi].uv_lcl_addr))) {
|
|
/*
|
|
* Neighbor has lower metric to origin (or has same metric
|
|
* and lower IP address) -- it becomes the dominant router,
|
|
* and vif is no longer a child for me.
|
|
*/
|
|
VIFM_CLR(vifi, r->rt_children);
|
|
VIFM_CLR(vifi, r->rt_leaves);
|
|
r->rt_dominants [vifi] = src;
|
|
r->rt_subordinates[vifi] = 0;
|
|
r->rt_leaf_timers [vifi] = 0;
|
|
update_table_entry(r);
|
|
}
|
|
else if (metric > UNREACHABLE) { /* "poisoned reverse" */
|
|
/*
|
|
* Neighbor considers this vif to be on path to route's
|
|
* origin; if no subordinate recorded, record this neighbor
|
|
* as subordinate and clear the leaf flag.
|
|
*/
|
|
if (r->rt_subordinates[vifi] == 0) {
|
|
VIFM_CLR(vifi, r->rt_leaves);
|
|
r->rt_subordinates[vifi] = src;
|
|
r->rt_leaf_timers [vifi] = 0;
|
|
update_table_entry(r);
|
|
}
|
|
}
|
|
else if (src == r->rt_subordinates[vifi]) {
|
|
/*
|
|
* Current subordinate no longer considers this vif to be on
|
|
* path to route's origin; it is no longer a subordinate
|
|
* router, and we set the leaf confirmation timer to give
|
|
* us time to hear from other subordinates.
|
|
*/
|
|
r->rt_subordinates[vifi] = 0;
|
|
if (uvifs[vifi].uv_neighbors == NULL ||
|
|
uvifs[vifi].uv_neighbors->al_next == NULL) {
|
|
VIFM_SET(vifi, r->rt_leaves);
|
|
update_table_entry(r);
|
|
}
|
|
else {
|
|
r->rt_leaf_timers [vifi] = LEAF_CONFIRMATION_TIME;
|
|
r->rt_flags |= RTF_LEAF_TIMING;
|
|
}
|
|
}
|
|
|
|
}
|
|
else if (src == r->rt_dominants[vifi] &&
|
|
(metric > r->rt_metric ||
|
|
(metric == r->rt_metric &&
|
|
ntohl(src) > ntohl(uvifs[vifi].uv_lcl_addr)))) {
|
|
/*
|
|
* Current dominant no longer has a lower metric to origin
|
|
* (or same metric and lower IP address); we adopt the vif
|
|
* as our own child.
|
|
*/
|
|
VIFM_SET(vifi, r->rt_children);
|
|
r->rt_dominants [vifi] = 0;
|
|
if (metric > UNREACHABLE) {
|
|
r->rt_subordinates[vifi] = src;
|
|
}
|
|
else if (uvifs[vifi].uv_neighbors == NULL ||
|
|
uvifs[vifi].uv_neighbors->al_next == NULL) {
|
|
VIFM_SET(vifi, r->rt_leaves);
|
|
}
|
|
else {
|
|
r->rt_leaf_timers[vifi] = LEAF_CONFIRMATION_TIME;
|
|
r->rt_flags |= RTF_LEAF_TIMING;
|
|
}
|
|
update_table_entry(r);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* On every timer interrupt, advance the timer in each routing entry.
|
|
*/
|
|
void age_routes()
|
|
{
|
|
register struct rtentry *r;
|
|
register struct rtentry *prev_r;
|
|
register vifi_t vifi;
|
|
|
|
for (prev_r = (struct rtentry *)&routing_table, r = routing_table;
|
|
r != NULL;
|
|
prev_r = r, r = r->rt_next) {
|
|
|
|
if ((r->rt_timer += TIMER_INTERVAL) < ROUTE_EXPIRE_TIME) {
|
|
/*
|
|
* Route is still good; see if any leaf timers need to be
|
|
* advanced.
|
|
*/
|
|
if (r->rt_flags & RTF_LEAF_TIMING) {
|
|
r->rt_flags &= ~RTF_LEAF_TIMING;
|
|
for (vifi = 0; vifi < numvifs; ++vifi) {
|
|
if (r->rt_leaf_timers[vifi] != 0) {
|
|
/*
|
|
* Unlike other timers, leaf timers decrement.
|
|
*/
|
|
if ((r->rt_leaf_timers[vifi] -= TIMER_INTERVAL) == 0){
|
|
VIFM_SET(vifi, r->rt_leaves);
|
|
update_table_entry(r);
|
|
}
|
|
else {
|
|
r->rt_flags |= RTF_LEAF_TIMING;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else if (r->rt_timer >= ROUTE_DISCARD_TIME) {
|
|
/*
|
|
* Time to garbage-collect the route entry.
|
|
*/
|
|
discard_route(prev_r);
|
|
r = prev_r;
|
|
}
|
|
else if (r->rt_metric != UNREACHABLE) {
|
|
/*
|
|
* Time to expire the route entry. If the gateway is zero,
|
|
* i.e., it is a route to a directly-connected subnet, just
|
|
* set the timer back to zero; such routes expire only when
|
|
* the interface to the subnet goes down.
|
|
*/
|
|
if (r->rt_gateway == 0) {
|
|
r->rt_timer = 0;
|
|
}
|
|
else {
|
|
del_table_entry(r, 0, DEL_ALL_ROUTES);
|
|
r->rt_metric = UNREACHABLE;
|
|
r->rt_flags |= RTF_CHANGED;
|
|
routes_changed = TRUE;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Mark all routes as unreachable. This function is called only from
|
|
* hup() in preparation for informing all neighbors that we are going
|
|
* off the air. For consistency, we ought also to delete all reachable
|
|
* route entries from the kernel, but since we are about to exit we rely
|
|
* on the kernel to do its own cleanup -- no point in making all those
|
|
* expensive kernel calls now.
|
|
*/
|
|
void expire_all_routes()
|
|
{
|
|
register struct rtentry *r;
|
|
|
|
for (r = routing_table; r != NULL; r = r->rt_next) {
|
|
r->rt_metric = UNREACHABLE;
|
|
r->rt_flags |= RTF_CHANGED;
|
|
routes_changed = TRUE;
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Delete all the routes in the routing table.
|
|
*/
|
|
void free_all_routes()
|
|
{
|
|
register struct rtentry *r;
|
|
|
|
r = (struct rtentry *)&routing_table;
|
|
|
|
while (r->rt_next)
|
|
discard_route(r);
|
|
}
|
|
|
|
|
|
/*
|
|
* Process an incoming neighbor probe message.
|
|
*/
|
|
void accept_probe(src, dst, p, datalen, level)
|
|
u_long src;
|
|
u_long dst;
|
|
char *p;
|
|
int datalen;
|
|
u_long level;
|
|
{
|
|
vifi_t vifi;
|
|
|
|
if ((vifi = find_vif(src, dst)) == NO_VIF) {
|
|
log(LOG_INFO, 0,
|
|
"ignoring probe from non-neighbor %s", inet_fmt(src, s1));
|
|
return;
|
|
}
|
|
|
|
if (!update_neighbor(vifi, src, DVMRP_PROBE, p, datalen, level))
|
|
return;
|
|
|
|
report(ALL_ROUTES, vifi, src);
|
|
}
|
|
|
|
struct newrt {
|
|
u_long mask;
|
|
u_long origin;
|
|
int metric;
|
|
int pad;
|
|
};
|
|
|
|
int compare_rts(r1, r2)
|
|
register struct newrt *r1;
|
|
register struct newrt *r2;
|
|
{
|
|
register unsigned long m1 = ntohl(r1->mask);
|
|
register unsigned long m2 = ntohl(r2->mask);
|
|
register unsigned long o1, o2;
|
|
|
|
if (m1 > m2)
|
|
return (1);
|
|
if (m1 < m2)
|
|
return (-1);
|
|
|
|
/* masks are equal */
|
|
o1 = ntohl(r1->origin);
|
|
o2 = ntohl(r2->origin);
|
|
if (o1 > o2)
|
|
return (1);
|
|
if (o1 < o2)
|
|
return (-1);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Process an incoming route report message.
|
|
*/
|
|
void accept_report(src, dst, p, datalen, level)
|
|
u_long src, dst, level;
|
|
register char *p;
|
|
register int datalen;
|
|
{
|
|
vifi_t vifi;
|
|
register int width, i, nrt = 0;
|
|
int metric;
|
|
u_long mask;
|
|
u_long origin;
|
|
struct newrt rt[4096];
|
|
|
|
if ((vifi = find_vif(src, dst)) == NO_VIF) {
|
|
log(LOG_INFO, 0,
|
|
"ignoring route report from non-neighbor %s", inet_fmt(src, s1));
|
|
return;
|
|
}
|
|
|
|
if (!update_neighbor(vifi, src, DVMRP_REPORT, NULL, 0, level))
|
|
return;
|
|
|
|
if (datalen > 2*4096) {
|
|
log(LOG_INFO, 0,
|
|
"ignoring oversize (%d bytes) route report from %s",
|
|
datalen, inet_fmt(src, s1));
|
|
return;
|
|
}
|
|
|
|
while (datalen > 0) { /* Loop through per-mask lists. */
|
|
|
|
if (datalen < 3) {
|
|
log(LOG_WARNING, 0,
|
|
"received truncated route report from %s",
|
|
inet_fmt(src, s1));
|
|
return;
|
|
}
|
|
((char *)&mask)[0] = 0xff; width = 1;
|
|
if ((((char *)&mask)[1] = *p++) != 0) width = 2;
|
|
if ((((char *)&mask)[2] = *p++) != 0) width = 3;
|
|
if ((((char *)&mask)[3] = *p++) != 0) width = 4;
|
|
datalen -= 3;
|
|
|
|
do { /* Loop through (origin, metric) pairs */
|
|
if (datalen < width + 1) {
|
|
log(LOG_WARNING, 0,
|
|
"received truncated route report from %s",
|
|
inet_fmt(src, s1));
|
|
return;
|
|
}
|
|
origin = 0;
|
|
for (i = 0; i < width; ++i)
|
|
((char *)&origin)[i] = *p++;
|
|
metric = *p++;
|
|
datalen -= width + 1;
|
|
rt[nrt].mask = mask;
|
|
rt[nrt].origin = origin;
|
|
rt[nrt].metric = metric;
|
|
++nrt;
|
|
} while (!(metric & 0x80));
|
|
}
|
|
qsort((char*)rt, nrt, sizeof(rt[0]), compare_rts);
|
|
start_route_updates();
|
|
for (i = 0; i < nrt; ++i)
|
|
update_route(rt[i].origin, rt[i].mask, (rt[i].metric & 0x7f),
|
|
src, vifi);
|
|
|
|
if (routes_changed && !delay_change_reports)
|
|
report_to_all_neighbors(CHANGED_ROUTES);
|
|
}
|
|
|
|
|
|
/*
|
|
* Send a route report message to destination 'dst', via virtual interface
|
|
* 'vifi'. 'which_routes' specifies ALL_ROUTES or CHANGED_ROUTES.
|
|
*/
|
|
void report(which_routes, vifi, dst)
|
|
int which_routes;
|
|
vifi_t vifi;
|
|
u_long dst;
|
|
{
|
|
register struct rtentry *r;
|
|
register char *p;
|
|
register int i;
|
|
int datalen;
|
|
int width;
|
|
u_long mask;
|
|
u_long src;
|
|
|
|
src = uvifs[vifi].uv_lcl_addr;
|
|
|
|
p = send_buf + MIN_IP_HEADER_LEN + IGMP_MINLEN;
|
|
datalen = 0;
|
|
mask = 0;
|
|
|
|
for (r = routing_table; r != NULL; r = r->rt_next) {
|
|
|
|
if (which_routes == CHANGED_ROUTES && !(r->rt_flags & RTF_CHANGED))
|
|
continue;
|
|
|
|
/*
|
|
* If there is no room for this route in the current message,
|
|
* send the message and start a new one.
|
|
*/
|
|
if (datalen + ((r->rt_originmask == mask) ?
|
|
(width + 1) :
|
|
(r->rt_originwidth + 4)) > MAX_DVMRP_DATA_LEN) {
|
|
*(p-1) |= 0x80;
|
|
send_igmp(src, dst, IGMP_DVMRP, DVMRP_REPORT,
|
|
htonl(MROUTED_LEVEL), datalen);
|
|
|
|
p = send_buf + MIN_IP_HEADER_LEN + IGMP_MINLEN;
|
|
datalen = 0;
|
|
mask = 0;
|
|
}
|
|
|
|
if(r->rt_originmask != mask) {
|
|
mask = r->rt_originmask;
|
|
width = r->rt_originwidth;
|
|
if (datalen != 0) *(p-1) |= 0x80;
|
|
*p++ = ((char *)&mask)[1];
|
|
*p++ = ((char *)&mask)[2];
|
|
*p++ = ((char *)&mask)[3];
|
|
datalen += 3;
|
|
}
|
|
|
|
for (i = 0; i < width; ++i)
|
|
*p++ = ((char *)&(r->rt_origin))[i];
|
|
|
|
*p++ = (r->rt_parent == vifi && r->rt_metric != UNREACHABLE) ?
|
|
(char)(r->rt_metric + UNREACHABLE) : /* "poisoned reverse" */
|
|
(char)(r->rt_metric);
|
|
|
|
datalen += width + 1;
|
|
}
|
|
|
|
if (datalen != 0) {
|
|
*(p-1) |= 0x80;
|
|
send_igmp(src, dst, IGMP_DVMRP, DVMRP_REPORT,
|
|
htonl(MROUTED_LEVEL), datalen);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* Send a route report message to all neighboring routers.
|
|
* 'which_routes' specifies ALL_ROUTES or CHANGED_ROUTES.
|
|
*/
|
|
void report_to_all_neighbors(which_routes)
|
|
int which_routes;
|
|
{
|
|
register vifi_t vifi;
|
|
register struct uvif *v;
|
|
register struct rtentry *r;
|
|
int routes_changed_before;
|
|
|
|
/*
|
|
* Remember the state of the global routes_changed flag before
|
|
* generating the reports, and clear the flag.
|
|
*/
|
|
routes_changed_before = routes_changed;
|
|
routes_changed = FALSE;
|
|
|
|
|
|
for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
|
|
if (v->uv_neighbors != NULL) {
|
|
report(which_routes, vifi,
|
|
(v->uv_flags & VIFF_TUNNEL) ? v->uv_rmt_addr
|
|
: dvmrp_group);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If there were changed routes before we sent the reports AND
|
|
* if no new changes occurred while sending the reports, clear
|
|
* the change flags in the individual route entries. If changes
|
|
* did occur while sending the reports, new reports will be
|
|
* generated at the next timer interrupt.
|
|
*/
|
|
if (routes_changed_before && !routes_changed) {
|
|
for (r = routing_table; r != NULL; r = r->rt_next) {
|
|
r->rt_flags &= ~RTF_CHANGED;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Set a flag to inhibit further reports of changed routes until the
|
|
* next timer interrupt. This is to alleviate update storms.
|
|
*/
|
|
delay_change_reports = TRUE;
|
|
}
|
|
|
|
/*
|
|
* Send a route report message to destination 'dst', via virtual interface
|
|
* 'vifi'. 'which_routes' specifies ALL_ROUTES or CHANGED_ROUTES.
|
|
*/
|
|
int report_chunk(start_rt, vifi, dst)
|
|
register struct rtentry *start_rt;
|
|
vifi_t vifi;
|
|
u_long dst;
|
|
{
|
|
register struct rtentry *r;
|
|
register char *p;
|
|
register int i;
|
|
register int nrt = 0;
|
|
int datalen;
|
|
int width;
|
|
u_long mask;
|
|
u_long src;
|
|
|
|
src = uvifs[vifi].uv_lcl_addr;
|
|
p = send_buf + MIN_IP_HEADER_LEN + IGMP_MINLEN;
|
|
datalen = 0;
|
|
mask = 0;
|
|
|
|
for (r = start_rt; r != NULL; r = r->rt_next) {
|
|
/*
|
|
* If there is no room for this route in the current message,
|
|
* send it & return how many routes we sent.
|
|
*/
|
|
if (datalen + ((r->rt_originmask == mask) ?
|
|
(width + 1) :
|
|
(r->rt_originwidth + 4)) > MAX_DVMRP_DATA_LEN) {
|
|
*(p-1) |= 0x80;
|
|
send_igmp(src, dst, IGMP_DVMRP, DVMRP_REPORT,
|
|
htonl(MROUTED_LEVEL), datalen);
|
|
return (nrt);
|
|
}
|
|
if(r->rt_originmask != mask) {
|
|
mask = r->rt_originmask;
|
|
width = r->rt_originwidth;
|
|
if (datalen != 0) *(p-1) |= 0x80;
|
|
*p++ = ((char *)&mask)[1];
|
|
*p++ = ((char *)&mask)[2];
|
|
*p++ = ((char *)&mask)[3];
|
|
datalen += 3;
|
|
}
|
|
for (i = 0; i < width; ++i)
|
|
*p++ = ((char *)&(r->rt_origin))[i];
|
|
|
|
*p++ = (r->rt_parent == vifi && r->rt_metric != UNREACHABLE) ?
|
|
(char)(r->rt_metric + UNREACHABLE) : /* "poisoned reverse" */
|
|
(char)(r->rt_metric);
|
|
++nrt;
|
|
datalen += width + 1;
|
|
}
|
|
if (datalen != 0) {
|
|
*(p-1) |= 0x80;
|
|
send_igmp(src, dst, IGMP_DVMRP, DVMRP_REPORT,
|
|
htonl(MROUTED_LEVEL), datalen);
|
|
}
|
|
return (nrt);
|
|
}
|
|
|
|
/*
|
|
* send the next chunk of our routing table to all neighbors.
|
|
*/
|
|
int report_next_chunk()
|
|
{
|
|
register vifi_t vifi;
|
|
register struct uvif *v;
|
|
register struct rtentry *r;
|
|
register struct rtentry *sr;
|
|
register int i, n = 0;
|
|
static int start_rt;
|
|
|
|
if (nroutes <= 0)
|
|
return (0);
|
|
|
|
/*
|
|
* find this round's starting route.
|
|
*/
|
|
for (sr = routing_table, i = start_rt; --i >= 0; ) {
|
|
sr = sr->rt_next;
|
|
if (sr == NULL)
|
|
sr = routing_table;
|
|
}
|
|
/*
|
|
* send one chunk of routes starting at this round's start to
|
|
* all our neighbors.
|
|
*/
|
|
for (vifi = 0, v = uvifs; vifi < numvifs; ++vifi, ++v) {
|
|
if (v->uv_neighbors != NULL) {
|
|
n = report_chunk(sr, vifi,
|
|
(v->uv_flags & VIFF_TUNNEL) ? v->uv_rmt_addr
|
|
: dvmrp_group);
|
|
}
|
|
}
|
|
if (debug)
|
|
printf("update %d starting at %d of %d\n", n, start_rt, nroutes);
|
|
start_rt = (start_rt + n) % nroutes;
|
|
return (n);
|
|
}
|
|
|
|
|
|
/*
|
|
* Print the contents of the routing table on file 'fp'.
|
|
*/
|
|
void dump_routes(fp)
|
|
FILE *fp;
|
|
{
|
|
register struct rtentry *r;
|
|
register int i;
|
|
|
|
fprintf(fp,
|
|
"Multicast Routing Table (%u %s)\n%s",
|
|
nroutes, (nroutes == 1) ? "entry" : "entries",
|
|
" Origin-Subnet From-Gateway Metric In-Vif Out-Vifs\n");
|
|
|
|
for (r = routing_table; r != NULL; r = r->rt_next) {
|
|
|
|
fprintf(fp, " %-15s %-15s ",
|
|
inet_fmts(r->rt_origin, r->rt_originmask, s1),
|
|
(r->rt_gateway == 0) ? "" : inet_fmt(r->rt_gateway, s2));
|
|
|
|
fprintf(fp, (r->rt_metric == UNREACHABLE) ? " NR " : "%4u ",
|
|
r->rt_metric);
|
|
|
|
fprintf(fp, "%7u ",
|
|
r->rt_parent);
|
|
|
|
for (i = 0; i < numvifs; ++i) {
|
|
if (VIFM_ISSET(i, r->rt_children)) {
|
|
fprintf(fp, " %u%c",
|
|
i, VIFM_ISSET(i, r->rt_leaves) ? '*' : ' ');
|
|
}
|
|
}
|
|
fprintf(fp, "\n");
|
|
}
|
|
fprintf(fp, "\n");
|
|
}
|
|
|
|
struct rtentry *determine_route(src)
|
|
u_long src;
|
|
{
|
|
struct rtentry *rt;
|
|
|
|
for (rt = routing_table; rt != NULL; rt = rt->rt_next) {
|
|
if (rt->rt_origin == (src & rt->rt_originmask))
|
|
break;
|
|
}
|
|
return rt;
|
|
}
|
|
|